1. Field of the Invention
The present invention relates generally to a magnetic recording medium that is loaded in the card slot of electronic equipment such as a digital still camera, a digital video camera, a laptop computer, etc. More particularly, the invention relates to a magnetic recording medium of a large recording capacity and small size that consists of a card-type disk drive which is loaded in the card slot of electronic equipment, and a magnetic disk cartridge which is exchangeably loaded in the disk drive.
2. Description of the Related Art
To record or reproduce information, a recording medium is removably inserted in the card slot of electronic equipment such as a digital still camera, a digital video camera, a laptop computer, etc. Such a recording medium in practical use are of a semiconductor memory type, a hard disk type, an optical disk type, a magnetic disk type (e.g., a floppy disk type), etc.
Among these recording media, semiconductor memories are most widely used because they are easy to handle and have a relatively large recording capacity. However, they are relatively expensive. Because of this, in digital cameras employing the semiconductor memory, the photographed image data is transferred to a PC and stored, the data is deleted from the memory, and the semiconductor memory is repeatedly used.
Optical disks have a large recording capacity for its size. For example, an optical disk with a size of 35 mmxc3x9741 mmxc3x9711 mm can store 256 MB of data. Optical disks with a recording capacity of 412 MB are about to be realized. However, optical disks have the disadvantage that its recording speed is slow, because their writing time is time-consuming.
Some magnetic disks such as a floppy disk have a small size of 50 mmxc3x9755 mmxc3x972 mm. Such a small magnetic disk can be exchangeably loaded in a disk drive of a size that can be inserted into the card slot of a PC, etc. However, the recording capacity is as small as 40 MB and insufficient to record image data photographed by a camera. In addition, the size is not suitable for digital cameras.
With the spread of PCs, digital cameras have spread rapidly in recent years because of the simplicity of recording, enhancement in picture quality due to the development of imaging elements, possibility of data deletion and transmission, recording capacity size, etc. However, the method of use is restricted, because recording media are limited in cost and recording capacity, as described above. For instance, since recording media are very expensive, a single camera has only a single recording medium, which is repeatedly used. That is, when the recording medium is filled with data, the data is transferred to a PC and deleted. Because of this, there are cases where the recording medium is filled up during a trip. In such a case, the recording medium cannot be stored along with data and cannot be given to a person.
The present invention has been made in view of the above-described circumstances. Accordingly, it is the primary object of the present invention to provide a magnetic recording medium which is large in recording capacity, low in cost, and small in size so that the data photographed by a digital camera can be stored or given to a person.
To achieve this end and in accordance with the present invention, there is provided a magnetic recording medium comprising a card-type disk drive that is loaded in a card slot of electronic equipment, and a magnetic disk cartridge that is loaded in the disk drive. The magnetic disk cartridge rotatably houses a flexible magnetic disk in a housing equipped with a shutter. The disk drive has a length of 38 to 55 mm, a width of 35 to 51 mm, and a thickness of 3 to 5 mm, and comprises a drive mechanism for rotating the magnetic disk of the magnetic disk cartridge loaded in the disk drive; a magnetic head for magnetically recording or reproducing information on or from the magnetic disk; and an electric connection portion for electrically connecting the drive mechanism and the magnetic head with an electronic circuit provided in the electronic equipment. The magnetic disk cartridge has a length of 25 to 36 mm, a width of 25 to 36 mm, and a thickness of 1 to 3 mm. The magnetic disk comprises a magnetic recording medium of high-recording density employing barium ferrite powder and has a recording capacity of 200 megabytes or larger.
The card slot of the electronic equipment in which the disk drive is loaded may be a newly provided dedicated slot. For example, if a dedicated slot is disposed near an insertion slot provided for conventional magnetic recording media, users can use both the conventional magnetic recording media and the magnetic recording medium of the present invention. In this case, the existing recording media will not be wasted.
The xe2x80x9cmagnetic recording medium of high-recording density employing barium ferrite powderxe2x80x9d is a magnetic disk containing barium ferrite powder in a magnetic layer, and employs a material capable of high recording density.
According to the magnetic recording medium of the present invention constructed as described above, the disk drive has a length of 38 to 55 mm, a width of 35 to 51 mm, and a thickness of 3 to 5 mm. Therefore, it is suitable for a PC such as a laptop, a digital camera, a video camera, etc. The magnetic disk cartridge has a length of 25 to 36 mm, a width of 25 to 36 mm, and a thickness of 1 to 3 mm and is thus small in size. However, the magnetic disk is a magnetic recording medium with a magnetic layer of high recording density containing barium ferrite powder, and has a recording capacity of 200 megabytes or larger. Therefore, the magnetic disk cartridge is suitable for use in a digital camera and easy to handle. In addition, the magnetic disk cartridge can be manufactured at a low cost, because it comprises a magnetic disk. The magnetic disk cartridge recorded can be stored as it is, or it can be given to a person.
According to the magnetic recording medium of the present invention, the size of the disk drive is one third or less of the size of the digital camera viewed from the front. The magnetic medium of about 2 mm in thickness which has a magnetic disk of about 28 mm in diameter can be loaded in the disk drive. Thus, the present invention is capable of realizing a magnetic medium which is conveniently portable and easy to use.
Further in accordance with the magnetic recording medium of the present invention, the disk of the above-described size can have a recording capacity of 500 megabytes. In such a case, the magnetic recording medium can store 500 photographs on a single disk. The price can be realized at a few hundred yen, so the practical effect is extremely great.